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The Best Glues For Luthiere


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hi i'm sure the has been asked already but i can't find the thread for it, so i'm gonna ask for myself... what is the best glue for luthiere? for wood bonded to wood applications, like laminating tops, joining tops and 2-piece bodies, laminating necks, scarf joints on neck, gluing the headplate to the neck, and the ever so important gluing the neck to the body? i've been using regular old titebond the original kind... in a recent fine wood working test it tested plently strong enough, even stronger than hide glue in a few catagories... but i've heard that since this glue is plastic based or, since it has some sort of plastic in it, it has a detrimental effect on the sound waves traveling through the wood of the guitar?... and that hide glue since it does not contain plastics does not have this same effect?... and also that hide glue has a sort of sealing quality... that it will sort of seal the end grain of woods? anyway, i'm not sure of any of these myth or truths or theories but i'm hoping that someone here does... i've been contemplating using hide glue for quite a while now, but is all the extra work and cost worth it in the long run? i know hide glue is easier to disassemble, but if that is one of the only benefits i'd like to know... thanks so much any and all advice would be greatly appreciated... thanks again, jonny p.s. is that liquid hide glue anything like regular hide glue?

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Titebond is good, and has a longer open time than HHG(simple, easy, ready to go and effective). HHG offers some advantages(speed, time tested success, dries harder, simpler to dis-assemble and re-assemble) and disadvantages(lower working time, requires heating, lower shelf life in a ready state), it is a great glue. Liquid HG in a bottle is not the same as HHG. If you are interested in a glue with similar charictoristics to HHG, but with longer open time and usable at lower temps, look into fish glue.

You can't go wrong with either of these glues, so try them both and use what works best. My take on the "damping" factor of Titebond, it is not significant when joints are made properly, I personally believe people who argue strongly against its use, have to use a poorly made joint as an example that could develop measurable problems. That of course is just my opinion.

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I think most people don't want to spend the big bucks on a glue pot, expensive if you are using it only occasionally. Of course with a repair on an old instrument thats the way to go since you don't want to change the makers glue choice.

I have heard various things about PVA on sound boards, flexible or more rigid, Sorry but its Bla Bla Bla to me these days. I would say most all production shops use some sort of PVA Glue acoustic or electric as do most builders I know.

Worrying about sealing wood should be determined by what finish not what glue you use. Wood breaths no matter what you do It's almost impossible to stop that process (OK within most budgets it is).

Just stick with good old type II PVA and you will not have to worry about your 30 year old guitar and the replacement fingerboard someone is doing.

Besides it's cheap and does the job what more can you say. and comes in many different versions all with similar properties. I would just like to add for the very reason you worry about repairs don't use Type III waterproof PVA glue, this may cause some removal problems down the road for others. I dont know if this is true but it makes some sense.

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Woodenspoke,

You don't need to buy an expensive glue pot, you can buy a small crock pot at a garage sale place marble in the bottom, and your in business(people that use it regularly just keep the pot warm and it is always ready to go, so I think it is something that one can get used to). I wouldn't shy away from HHG for that reason. It does require speed in assembly, but also sets faster(downside/upside). It is also very nice as far as clean up. HHG has its strengths for sure, and that speed in cure time is a nice plus for a production shop(as faster cure means they can move faster, of course there are other oprions for faster curing glues also). As far as soundboards go, I think the issue is more with creep (NOTE; a soundboard moves a hella lot more than say a set neck or joined body blank, very different requirements and potential benifits/problems), and I have used both methods for bracing on my soundboards and am not worried too much about a possible downside to PV. As far as sealing, there may be some benifits to using HHG on end grain joints, but they should be avoided anyway (kinda mute point in that sense). HHG should be sealed with a finish, and although it could potentially be used as a grain filler I think there are better options. I use HHG to place my bias tape on sides of my acoustics(crack migration prevention, and adds stiffness), but I have to seal the HHG to prevent it from rotting out.

I still say both Titebond and HHG are super good choices for building. Titebond is certainly about as easy as pie to use and is always ready, has a good shelf life, nice open time, more than strong enough, bonds to most woods extreamly well (can't ask for much more than that). HHG is time tested, strong, cleans up very well(big points if you are glueing a lot of bracing, linings, and so forth), is easy to repair, sets very quickly, dries very hard, low potential for creep, adhears to most woods extreamly well.

Just thought I would offer a bit more on the HHG FWIW. Still give two big thumbs up to Titebond also.

Peace,Rich

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Definitions I pulled from my notes:

Hide Glue:

Made from animals, this glue has been the traditional adhesive of luthiers for hundreds of years. It is still the most commonly used glue in the bowed instrument family. Available dry in sheet, flake, or granular form this glue must be rehydrated be adding water and warming in a doulbe boiler of glue pot. Once the glue is ready you have about one to two minutes of open working time. The glue must be applied, the pieces assembled and clamped within this time. You can extend this open time slightly by thinning the glue with a small amount of water or heating the wood with a heat gun, hair dryer or mircrowave. The glye will cure very hard and brittle in about 24 hours and it heat resistant to about 160°. Excess glue can be cleaned up easily with warm water. Hide glue sands well. It can last years in the dry form, but once rehydrated has a short shelf life of only three to four days before becoming rancid. You should only make slightly more than you need for each repair. Animal glues have the advantage of easy disassembly with a hot knife or shocking the joint will break it loose because the glue is hard and brittle. Carefully applied moisture also works well for disassembly. The main drawback is that it absorbs moisture from the air and eventually weakens. It is an excellent glue for repairing acoustic guitar tops due to is hard semitransparent glue line.

Polyvinel Acetate:

PVA, White glue, "Elmer's glue": dries transparent, it is quite strong and is more water-soluble than aliphatic resin. Althought not widely used in guitar building, some makers recommend it for neck joints. It's cold flow (creep under sustained loading) can be an important asset in mortise and tenon joints. However, this creep can be detrimental when it occurs in edge gluing and lamination. It's a rubbery, flexible glue and clogs sandpaper easily. Delveloped in the 1940's PVA has a long shelf life, is nontoxic and safe to use around children.

Aliphatic Resin:

"Titebond", Yellow glue, Carpenters glue: dries a creamy translucent, very hard and strong. Yellow glue is simply a higher quality of white glue, with some color added. The term "aliphatic resin" is used to differentiate the white from the yellow. This is the most widely used glue in guitar building. Yellow glue is water souluble but more moisture resistant than PVA. It is also solvent resistant. It's higher initial tack and creep resistance make it ideal for edge joining and laminating. It has a higher heat resistamce to about 140°. Rapid curing time and hardness make it more sandable but any excess should be removed prior to sanding. Aliphatic glues require light to moderate clamping pressure. Avoid overclamping since this can force all the flue from the joing. This glue can be softened with water or heat, if necessary, to separate a joing. It has a shelf life of sic to eight months and is also nontoxic.

I figured this would help understand a little better :D

L8er,

Scab

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Can I just add to the PVA bit - (a company I used to work for was a huge producer of emulsion polymers like PVA) - there's 4 different performance grades from craft or school glue up to structural. You can include cross-linking additives or cook them into the polymer chain - cross linking of the polymer chains as it dries/cures stops any creep tendancies and also adds a lot of heat resistance where most of these families of polymers would start to get a bit softer with heat. Cross-linked types are very water-resistant.

Sadly the companies formulating PVA glues from the polymer rarely clarify on the tubs/bottles/cans which grade or the filler + water content they add to cheapen the product. Steer away from cheap products, they have little polymer in them and will usually not be the cross-linking type. You get what you pay for but also have to pay a little premium for the big brands.

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Short answer: depends on the application.

Titebond is great for most structural work in a guitar. And I've yet to see anything even remotely convincing in terms of 'does titebond affect sound negatively' on an electric guitar. Acoustic, yes, maybe, electric, not s'much, and both types have been built with titebond for pretty much all joints, and have sounded great.

I use Titebond for most applications, because I know it's strong enough, doesn't creep as much as the waterproof varieties (titebond II, III, etc.), dries harder, and has a more invisible glue line than most polyurethane glues (which require even more clamping). Hot hide gets used in some places, polyurethane or epoxy or thick CA for gluing CF to wood, epoxy or titebond for laminating (usually titebond for necks, poly for multiple thinner plys, like headstock backstraps), titebond for set neck joints (although epoxy can be good too, given the end-grain component), epoxy for fingerboards, CA for inlays, fret ends...

each glue has its uses. But the 'old standard' remains Titebond Original.

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